Field of the Invention
The present invention relates to microneedles used for drug administration and microneedle assemblies having a microneedle and an applicator.
Discussion of the Background
Drug administration using a microneedle is known as a method of administration of drugs such as vaccine into the body (for example, see PTLs 1 and 2). The microneedle includes a plurality of piercing projections having a needle-shape formed on the surface of a substrate. In the administration method using a microneedle, the substrate is pressed against the skin so that the piercing projections puncture the skin to form holes, through which a drug is delivered into the skin. Since the piercing projection has a length that does not reach nerve cells in the dermis layer of the skin, the administration method using a microneedle reduces pain caused by puncturing the skin compared with an administration method using an injection needle. Further, in the administration method using a microneedle, a drug is administered into the skin, which is abundant in antigen-presenting cells. Accordingly, the dose of the drug is reduced compared with a subcutaneous injection.
PTL 1: JP-A-2006-345983
PTL 2: JP-A-2006-341089